Which system are ships of 300 gross tons or more required to be equipped with?

• A. GMDSS
• B. MMSI
• C. AIS
• D. VDR

Answer: (A)

Global Maritime Distress and Safety System (GMDSS) is the safety communications framework SOLAS requires ships of 300 gross tons and above on international voyages to carry. It ensures rapid distress signaling and coordinated safety communications through satellite and radio networks, with automatic distress signaling and emergency communications coordination. That overarching requirement is why this system is the correct answer for ships of that size.

MMSI is the unique radio identity used within GMDSS, so it’s a component of the system rather than the whole thing. AIS provides automatic identification and tracking to aid collision avoidance and situational awareness, but it isn’t the stand-alone requirement that fulfills the 300 GT international voyage safety mandate. VDRs are voyage data recorders; they’re required for certain vessel types and sizes, but not simply for all ships of 300 gross tons.